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Body Language and Lie Detection

Perhaps, the first ever and most interesting record of detecting lies or catching liars by checking the bodily or physiological cues or indicators goes back to 3,000 years ago. The process of lie detection inside the imperial courts of ancient China was entirely focused on salivation (secretion of saliva). What is the exact logic behind it? If a person produces less or no saliva inside her mouth then it's most likely that she is under stress while speaking with/to or answering the questions asked by another person.

Before starting to speak or to give answers, an accused person or a suspect was ordered to keep a lump of dry rice in her mouth. As speaking or answering come to an end, the person was ordered to take out or spit the rice from her mouth for visual inspection. If the rice was found to be moist or wet due to normal secretion of saliva during the question-answering session then it was assumed that the person was telling the truth because she wasn't speaking without any stress or fear. Wasn't it simplest and straightforward? Obviously, chewing rice was much better than getting tortured.

We do lie verbally but we've set out on the mission to check the nonverbal cues of lying. From indirectly checking the saliva inside the mouth to detecting the cues, signs or indicators in body language, we look for fear, guilt, stress, anxiety or nervousness. There are several other ancient methods of lie detection. Surprisingly, some of them are still used, such as licking a red hot spoon in Bedouin tribal members of Arabia. Truth teller wouldn't get a scar or burnt mark on tongue, due to the normal level of saliva keeping it enough wet.

Although tongue is solely responsible for generating the deceptive speech, we can't stop ourselves from looking at each other's faces or into eyes look even while we aren't talking. That's why we've developed different (mis)beliefs around the face about the (reliable) cues, signs or indicators of lying, over the thousands of years. Some of them are universal e. g. a person not looking into your eyes or looking away is lying to you. However, it's not at all necessary that people of every culture and/or ethnicity exactly do the same.

Most of us are naturally inclined to blindly believe in and follow the tips, tricks or techniques that are shown in or shared by commercial movies, online videos and TV serials to catch liars in the real-time. Lie to me was a famous TV serial in which the central character Dr. Cal Lightman was depicted as an expert that could catch liars by detecting their facial micro-expressions. However, they can't be detected in the real-time without a formal training and rigorous practice.

(Image Courtesy: Fox Broadcasting Company)

"So, Exactly how GOOD (%) we are in detecting lies? Certainly, we aren’t 100% good. Even our technological tools aren’t 100% good/accurate in catching lies."
One of the 55 slides from my recent presentation
(Note: Please read #Special Note (below) for more details.)

Whenever it comes to determining if a person is lying or telling the truth based on the nonverbal or body language cues, signs or indicators; there's a little disagreement among people, especially between two tentatively different groups.
First group (A) is mostly made up of academic researchers and/or scientists. Second group (B) is largely made up of the professionals such as (counter-)intelligence officers/agents, lie detection professionals, law enforcement officers, lie detection experts, forensic interviewers, interrogators and investigators who do face people.

On one hand, if not all but most studies that have been conducted so far were by the academic researchers from western cultures, countries, universities and/or institutions. They mostly involved the subjects of very specific backgrounds e. g. university students. Also, most experiments have been conducted in controlled environments or inside labs. Of course, conducting elaborate experiments or studies by involving the real suspects, criminals or offenders might be posing some difficulties, challenges and/or limitations for researchers.

On the other hand, it's only the professionals who ask questions or interrogate to get confessions from the real suspects or criminals. Unlike a limited amount of, chosen or specific subjects participating in experiments conducted in controlled environments or labs; they do face the real people belonging to different ages and genders with diverse social, ethnic, genetic, physical, cultural, educational, developmental, psychological and economical backgrounds, conditions and/or histories. They do matter a lot.

Both groups or even the members of any single group among themselves don't completely agree with each other about (some) nonverbal or body language cues as reliable and/or strong indicators of lying. Indeed, members of any single or both groups have their own conclusions that have been entirely derived from their own studies, findings, observations, experiments and/or experiences originating from entirely different sets of people they faced so far.

After going through the above facts or bitter truth, I'm quite sure that you clearly realize a great gap between both groups or parties i. e. A) Academics/scientists and B) Professionals/practitioners. Of course, there's a great difference in operating conditions, inclinations, obligations, challenges, exposures, limitations, thoughts, resources and/or methods of both groups or even among the members of any single group.

Despite of disagreements between both groups or even among the members of any single group, they do honestly share the single-most common goal or the greater challenge of bringing the criminals and offenders to justice by analyzing the different kinds of cues that suspects or criminals do subconsciously give away while lying or deceiving verbally.


Method of lie detection by analyzing of body language is repeatedly criticized as 'pseudoscientific' by (some) academic researchers and/or scientists. Hence, I really wonder if a truly 'scientific' lie detection method is strictly supposed to be capable of predicting beforehand, with a mathematical accuracy. Can any lie detection expert, interrogator or professional can predict a nonverbal cue or cues of lying, well before facing the person to be interrogated, interviewed, questioned or scrutinized? Or Is it always possible to anybody? Being an independent researcher, I've to challenge you to think over this.

If predictability of nonverbal or body language cues of lying is the sole qualifying criteria then it'll be satisfied in an ideal world in which every person's neural wiring, perception, personality, experiences, motivations, anxieties, ambitions, intentions, character, thoughts, ideology, memories and needs are exactly the same. What about the differences in social, ethnic, genetic, physical, cultural, educational, developmental, psychological and economical backgrounds, conditions and/or histories that subtly or overtly influence, govern or shape them in this world?

Still, most lie detection experts or professionals do agree that there's no single reliable, definite or universal cue of lying or verbal deception. Also, any single cue doesn't convey anything so multiple cues need to put in a cluster. However, a cluster of different cues doesn't help until it is timely and smartly capitalized by the investigator in search of the truth or reality. Actually, a suspect, a criminal or an offender needs to confess the crime or offense verbally or it needs to be proven in the court with evidences.

Hence, analysis of nonverbal or body language cues in the real-time is only a tool. It can and does help a questioner, an interviewer or an interrogator to dig deeper in the mind of the person under scrutiny. If the investigator is well trained and/or skilled in statement analysis and speech (para-language) analysis then it gives a huge advantage. Sometimes, mental smartness works much better or efficiently than pressure, confrontation, intimidation or physical torture.

Actually, determining if a person is telling a lie or a truth just by observing her body language with bare eyes is a little difficult and challenging for most of us, without a formal training. Also, some of the nonverbal or body language or cues are too small, swift or subtle, to be detected with bare eyes. For example, blinks can be detected with bare eyes but 4% to 8% pupil dilation can't be. That's why we need an electronic device or tracker for sure.

Apart of the skill, training, practice and sharp eyes required to detect the subtle nonverbal cues; the success of a (counter-)intelligence officer/agent, lie detection professional, law enforcement officer, lie detection expert, forensic interviewer, interrogator or investigator depends on the ability to stay mentally calm, curious, focused and balanced. Sometimes, indirect questions and/or eliciting statements works like magic.

A scene from movie "Liar Liar" (1997)
(Image Courtesy: Universal Pictures)

Starting from finding the cues of deception in nonverbal behavior or body language, we've gradually developed several methods of lie detection. According to a paper published in 2023 by Dr. Tim Brennen and Dr. Svein Magnussen (Department of Psychology, University of Oslo, Norway), there're seven different (available) methods of lie detection at present that have been most likely adapted by law enforcement or investigative agencies across the globe. Perhaps, it's the first time that you're coming to know about them. I didn't know about some of them, before reading the paper.

Along with the analysis of 1) Nonverbal Cues (or body language), 2) Systematic Analysis of Verbal Cues, 3) Manipulation of Statement Production, 4) Polygraphic Analysis, 5) Brain-based (Neuroscientific) Analysis, 6) Strategic Interviewing and 7) Analysis using an Artificial Intelligence (AI) tool have been included in the same list. Currently, AI based cue analysis is a slowly evolving method. However, it can certainly find and reveal the (kinds of) patterns that haven't been identified yet by us humans with organic or bioligical brains or intelligence.

Ability of deceiving (nonverbally) is very common in many creatures, including human beings. However, ability of lying or deceiving verbally could be reserved to human beings because we're the only species on this planet that can produce pre-specified sounds through our mouths. However, further research needs to done if other creatures have developed an ability of lying while using their own languages. Although one person can lie to the other person, no human being can lie to or or deceive any other creature verbally. Can you?

One of the 55 slides from my recent presentation
(Note: Please read #Special Note (below) for more details.)

Today, majority of the current human population is living inside the modern techno-industrial world. However, there're a few percent of people who do still live their lives in small groups, just like our remote ancestors did, hundreds or thousands of years ago. So why don’t we study Exactly how today’s tribal-indigenous-aborigional people catch a person while lying? It'll be quite interesting to find if they still rely on the nonverbal cues of lying or verbal deceit, just like most of our own ancestors or forefathers did or used to do over last thousands of years. Perhaps, tribal-indigenous-aborigional people might be using other methods or ordeals for confession.

However, both frequency and severity of massively damaging or devastating lies in the tribal-indigenous-aborigional world could be way more less in comparison to the modern techno-industrial world. The exact reasons behind the same could be the ones that do reveal the darker reality of the 'brighter' world in which millions of people get hallucinated, brainwashed, manipulated, intoxicated, illusioned, tricked, fooled, robbed, hunted, addicted, hijacked, enslaved, devastated or destroyed by convicing truths, fancier fictions, false promises, elaborate myths, powerful propaganda or above all - the utopian dreams.

Minimal requirements for living the life, higher frequency of face-to-face interactions, lesser (or no) materialistic ambitions, lesser (or no) personal possessions, higher level of interdependence, higher level of cooperation, greater emphasize on relations, smaller geographical territories, harsher punishments upon lying, strict moral obligations, smaller group sizes and higher level of empathy might have conditioned the tribal-indigenous-aborigional people to be more honest, truthful, realistic, verifiable and transparent.

"Surprisingly, how easily or quickly you get convinced by a lie is entirely dependent on you only. Yes! It’s you i. e. your own mental processing power, knowledge, perception, prejudices, needs, beliefs and/or biases."
- Body Language Insights (Book)

[#Special Note: This entire article has been inspired by and is partially based on the overall content of the same PowerPoint presentation that was given by me to students pursuing bachelor, masters and doctoral (Ph. D.) degrees and faculty members of National Forensic Sciences University (NFSU). It’s a public international university in India with the status of an Institution of National Importance. Also, it has 10 campuses in two different countries at present.


I was formally invited by the honorable dean of School of Behavioural Forensics (SBF) of the university to provide the guidance to the attendees, under the annual initiative of "An inter-disciplinary perspective on the Criminal Justice System". The presentation was delivered at Gandhinagar campus of the university, situated in the state of Gujarat (India) on 22nd January 2025.]

Related Articles:
1) *From Common Signs to Spotting Lies 2) Entire body can’t lie 3) Nonverbal Advantage in Investigation 4) My career saving lie detection 5) Face of liar(?) 6) Truth about Lying 7) Inside Interrogation Room

1 comment:

  1. Very interesting. Here’s my take based on over 40 years in the field. The idea that universal, accurate cues can detect deception is largely pseudoscience. While some behavioural patterns are commonly associated with lying, any practitioner or academic will tell you they are not reliable indicators of deception. People can be nervous for many reasons unrelated to lying, and conversely skilled liars often control their behaviour to appear truthful.

    Scientific studies suggest that deception detection is highly context-dependent and influenced by individual differences. Polygraphs, which measure physiological responses like heart rate and sweating, are also innacurate, because anxiety—not just deception—can trigger these reactions.

    An informed practitioner instead o of relying on supposed universal cues, instead advocate content-based analysis, such as examining inconsistencies in a person’s story or unexpected details. Methods like increasing cognitive load have shown promise but are still imperfect.

    Overall, while deception detection remains an area of study, there are no universal, scientifically validated cues for detecting lies with high accuracy.

    Bob Pointer
    Behavioural Intelligence Academy

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